COORDINATE-BASED FORM-FINDING OF IRREGULAR TENSEGRITY: ANALYSIS AND IMPLEMENTATION

摘要

A novel coordinate-based form-finding approach for irregular tensegrity structures is proposed in this paper. On the basis of two different forms of structural equilibrium equations, the estimated elemental self-stresses and nodal coordinates are constructed via the singular value decomposition of equilibrium matrix and eigenvalue decomposition of force density matrix. The configuration of tensegrity that satisfies the specified coordinates is determined through the iterative computation of selfstresses and nodal coordinates, and the constraint condition is introduced in the construction of the estimated nodal coordinates simultaneously. The convergent criterion is defined and the detailed algorithm procedure is listed. In the end, two illustrated examples are given to prove the validity of the algorithm. It is found that the structure can be assembled through the way that rigid struts hold up flexible cable net, just like wearing clothes. Members and joints are designed in detail for the easy construction of model. Numerical examples and physical models show that the proposed form-finding method is correct and efficient. As long as the formfinding algorithm is provided with topological relation and several known coordinates of nodes, it could be applied to find tensegrity structures that satisfy the given geometrical forms, and the creation of novel irregular tensegrity.